So I'm really trying to get a slightly better sound out of my 04' 4.6L F150. Not anything loud and raspy, or drone. Just a smooth strong sound. Instead of spending the money on purchasing a full catback, has anyone just purchased a good muffler and swapped it in. I like the magnaflow muffler...I have found a 5 X 8 X 18 muffler, but I'm trying to decide whether I should get a Center/Offset or Offset/Offset muffler to fit new piping up to. I should be able to use my existing hangers if I just cut the old muffler off?

Has anyone put a dynomax muffler on a 4.6L motor similar to my year? How do they sound? Most of the flowmaster mufflers are too loud and raspy for my liking, as are Gibsons, the Magnaflow is loud but not raspy or to loud from hearing clips, but it sounds pretty good.

Also, after looking under my truck...it seems as though the pipe in front of my muffler is a smaller diameter than the pipe coming out of my muffler? I didn't take any measurements yet, but I'm guessing 2.5" into muffler 3" coming out maybe?

Cory

 

Flowmaster 50 series is pretty mellow, I don't like the over priced glasspack style mufflers. But I am running straight 3" with a 2.5" bent tube in place of my muffler and a packed 5" Stainless Steel tip to clean up the sound a bit. Seems to scavenge well and sounds mean but clean. BTW my truck has a 5.4L. I am still looking for somebody that's running a zoomer system...
Zoomers Exhaust Works - Performance Exhaust Systems, Exhaust Tips, and Cat-backs

 

If you don't want a loud raspy exhaust its helps to have a muffler with a larger case volume. You can't generalize all flowmasters as loud and raspy because they make many series with different case volumes. For instance the 50 BB and 70BB2 mufflers are only slightly louder than stock and also have the largest case volume of any of the Flowmaster mufflers. The 50 SUV muffler is slightly louder than the two BB and BB2 mufflers but is not harsh mainly because of its case volume and drone chambers. FMs smallest case muffler will be its loudest muffler.

I had a Dynomax Ultra flow on my truck and I liked it, it was an oval muffler with glass packing. For the sound you want I look at a muffler with around an 18"-22" case length. Your exhaust should be 2.5" from behind the Y-pipe back. No problem with just replacing the muffler, lots of people do it. Trucks usually take a dual opposite offset muffler.